Face masks, such as surgical face masks, are worn by health care professionals to protect patients and wearers. Such masks can catch bacteria and viral particles shed from the wearer's mouth and nose. However, such masks are generally loose fitting with the wearer's exhalation gases flowing around the perimeter of the face mask, typically at the lower edges of the cheeks and around the chin of the wearer. Accordingly, concerns have arisen as to the effectiveness of such face masks in protecting patients (Edmiston C E Jr, et al. “Molecular epidemiology of microbial contamination in the operating room environment: Is there a risk for infection?” Surgery. (2005) 138:573-9, 579-82; and Lipp A, et al., “Disposable surgical face masks: a systematic review.” Can Oper Room Nurs J. 2005 23:20-1, 24-5, 33-8; each of which is incorporated herein by reference in its entirety). In addition, such face masks may be ineffective at protecting the wearer from hazards such as surgical smoke (Alp E. et al., “Surgical smoke and infection control.” Journal of Hospital Infection (2003) 62:1-5; Biggins J. et al., “The hazards of surgical smoke. Not to be sniffed at!” Br J Perioper Nurs. (2002) 12:136-8, 141-3; each of which is incorporated herein by reference in its entirety).
The human face presents a challenge for forming a seal between a face mask and the user's face. The human face is deeply contoured; moreover, the size and proportion of these contours vary widely between human faces.
Attempts have been made to better seal the perimeter of face masks. For example, U.S. Pat. No. 4,319,567 describes a thicker perimeter in the nasal bridge and lateral cheek areas, and U.S. Pat. No. 4,807,619 describes multiple layers of fibrous filter material allowing for greater facial conformity. Typically, face masks include a plastically deformable strip of metal or other material, to allow the user to customize the shape of the portion of the periphery of the mask that extends across the bridge of the nose. After loosely fitting the mask over the face, a user can plastically deform this member so as to help the mask maintain a close fit across the bridge of the nose.
Some face masks have incorporated a non-filtered exhalation valve. Such a design feature may allow exhaled gases to bypass the filter body due to less flow resistance, thereby providing greater comfort and less vapor-induced fogging. Examples of such devices include U.S. Pat. Nos. 7,188,622, 4,873,972, and 5,509,436; each of which is incorporated herein by reference in its entirety. However, none of these designs are applicable to the operating room environment, since the exhaled products are not filtered. In some embodiments herein, the teachings and apparatuses of the incorporated patents and articles may be specifically excluded.